Which phenomenon limits high performance proton exchange membrane's (PEM's) fuel cell ability to operate well below 0°C?

💡 Explanation

Ionomer phase separation constricts PEM pores because water freezes and segregates the hydrophobic and hydrophilic regions, resulting in a loss of proton conductivity due to reduced reactant transport. Therefore separation limits pore availibility, rather than ruptures from hydrogen embrittlement alone.

• Which outcome results when gate oxide thickness in a MOSFET decreases to nanoscale dimensions?
• Which outcome occurs when approximating electron orbitals increases?
• Which outcome occurs when applying rapid, uniform compression to supercooled liquid until well below its crystallization temperature?
• Which risk increases as inlet Reynold’s number approximates the limit for a microfluidic bioanalysis chip?
• Which outcome affects methanol production exposed to oscillating pressure?
• Which risk increases substantially during rapid isochoric water-to-steam phase transition in a closed autoclave?